JPH0380746B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method of manufacturing a long ceramic board using ceramic as a base material for use inside or outside buildings. More specifically, the present invention provides a method for manufacturing a building material that is a long plate formed by extrusion molding, has high weather resistance, high strength, and excellent design. [Conventional technology] Many materials have been used as building materials in the past, but ceramics (ceramic materials) have the best appearance and durability, and the question is whether this advantage could be used as a general material. has been considered. However, since ceramics involve a firing process,
For example, there was no technology to precisely manufacture large ceramic plates of 30 cm square or more, so we had no choice but to make small tiles and paste them together. Furthermore, ceramic plates are difficult to mold, and only simple shapes can be obtained. In order to solve this problem, a method of preventing deformation by hardening with a hydrated material such as cement before firing was considered, but this method deteriorated the strength and was prone to cracking, making it difficult to achieve the desired durability. I had doubts. Bricks have also been used in large quantities for construction, but they have not always been desirable in terms of size, aesthetics, and design. In recent years, long ceramic plates have been manufactured continuously, and JP-A-61-36160, JP-A-61-44752, JP-A-61-
44753, JP 61-44754, JP 62-21746, JP 62-21747, JP 62-21748, JP 62-
21749. These techniques involve vacuum extrusion molding and firing of clay made of potter's stone, feldspar, silica stone, etc. Compared to conventional techniques, the deformation is smaller and long ceramic plates can be produced, but they still prevent warping. It is not possible to reduce the thickness to 5 mm or less per 1 m, and it is not sufficient in terms of deformation and accuracy improvement. [Problems to be Solved by the Invention] It is an object of the present invention to provide a method for manufacturing a large ceramic plate that suppresses the decrease in dimensional accuracy due to deformation and has excellent aesthetics and design as described above. . [Means for Solving the Problems] The present invention is a method for manufacturing a long ceramic plate characterized by comprising the following steps. (1) Knead raw materials containing 10 to 50% by weight of wollastonite. (2) This kneaded raw material is extruded into a long plate shape by extrusion molding. (3) Perform the first firing at 600-1150°C. (4) Grind and glaze. (5) Perform the second firing at a temperature lower than the first firing temperature. [Function] Although firing shrinkage and firing deformation can be reduced, they cannot be eliminated. Therefore, in the present invention, firing shrinkage and deformation can be minimized by grinding after the first firing and performing the second firing. The present invention uses a raw material containing 10 to 50% by weight of wollastonite. Wollastonite is used as a raw material because ceramic plates can be fired quickly. When added to the raw materials, sintering can be performed quickly and sintering does not proceed. The first firing is performed at a relatively low temperature of 600 to 1150°C, and must be fired for a short time (maximum temperature maintained, within 1 hour, 5 minutes or more) so as not to advance sintering.
If the temperature exceeds 1150℃, sintering progresses too much and grinding becomes difficult. At temperatures below 600°C, firing shrinkage is not completed and there is much residual deformation. Also, if firing is performed for a long time, it becomes difficult to grind. There is residual deformation after firing for a short time. Grinding is performed using a sander, a grindstone, or a diamond tool. If the first firing is performed at a low temperature within the above firing temperature range, grinding is possible even with a metal tool. After grinding, glaze is applied and second firing is performed. By ending the shrinkage deformation in the first firing and setting the second firing temperature lower than the first firing temperature, no deformation occurs again. Since the second firing temperature is related to the type of glaze, it is determined by taking this into consideration. [Example] Raw materials kneaded with water according to the formulation shown in Table 1 were extruded into a hollow plate shape of 100 mm width x 15 mm thickness x 1500 mm length to create a molded body. After drying the molded body with far infrared rays, the temperature was raised to 1100℃ for 50 minutes using a roller hearth kiln, and then heated to 1100℃ for 10 minutes.
The mixture was passed through a calcination zone at ℃ and cooled to room temperature for 30 minutes.
The amount of deformation and grindability of the fired products were investigated. The results are shown in Table 1. The amount of deformation by firing in Table 1 indicates the amount of deformation δ (mm) per 1 m of fired product, as shown in Figure 1, and the average of 10 samples was taken. If there is a large amount of wollastonite in this way, the workability is good, and the precision can be easily improved by grinding, but since wollastonite crystals are fibrous, they become oriented during extrusion, and their drying Due to the anisotropy of firing shrinkage, the amount of deformation increases. For this reason, it is clear that 10 to 50% by weight of wollastonite is good. Next, regarding the composition No. 4 in Table 1, 500 to 1200
The first firing temperature, deformation amount, and grindability were investigated between 900°C and 900°C, and
A second firing was performed at 1150°C, and the amount of re-deformation was investigated. A roller hearth kiln was used for both the first and second firings, and the temperature was raised to the maximum temperature in 50 minutes.
The temperature was maintained at the maximum temperature for 30 minutes and then cooled for 30 minutes.
The results are shown in Tables 2 and 3. When the temperature of the second firing is higher than that of the first firing, re-deformation increases. If fired at a high temperature of 1200℃ or higher, the grindability will decrease and it will become impossible to process. 1st
If the firing is performed at a low temperature (700°C or less), the grindability is good, but since the second firing temperature cannot be raised, the final strength is low.

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〔Effect of the invention〕

According to the method of the present invention, the influence of firing deformation can be eliminated, dimensional accuracy is high, weather resistance is high,
It is now possible to easily manufacture long ceramic plates with arbitrary cross sections with high strength and excellent design through extrusion molding, which greatly contributes to the aesthetic appearance and workability of building interiors and exteriors. It is.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the procedure for measuring the amount of firing deformation in the example. δ...Amount of deformation.

Claims (1)

[Claims] 1 Raw materials containing 10 to 50% by weight of wollastonite are kneaded, extruded into a long plate, and heated to 600 to 1150°C.
1. A method for manufacturing a long ceramic board, which comprises performing a first firing at a temperature, followed by grinding and glazing, followed by a second firing at a temperature lower than the first firing temperature.